Now Efford, among scores of Labour MPs fearing Corbyn’s leadership could sink Labour, has fired off a series of incredulous tweets, making clear he is “amazed and disappointed” that Corbyn would choose “someone with history supporting Tories against Labour to run his campaign”.

Efford questions whether he is a ‘Red Tory’ - a term of abuse used by someone on social media for Labour politicians who are not left-wing enough for their liking.

Momentum has been organising hugely popular rallies in support of Corbyn’s re-election campaign.